Is 14710:1999 ( Reaffirmed 2004 ) W!rh.( v/'lco \\ d-fa%kl ­ RF!IR Indian Standard MEZ2-CRESOL -- SPECIFICATION ICS 71:080.15 @ BIS 1999 BUREAU MANAK OF BHAVAN, INDIAN STANDARDS ZAFAR MARG 9 BAHADUR SHAH NEW DELHI 110002 August 1999 Price Group 6 Aromatic Hydrocarbons and Related Products Sectional Committee, PCD 8 FOREWORD This Indian Standard was adopted by the Bureau of Indian Standards, after the draft finalized by the Aromatic Hydrocarbons Sectional Committee had been approved by the Petroleum,Coal and Related Products Division Council. m-Cresol is obtained by fractional distillation of crude cresol and further puritied by rectification. It is also known as meta-methylphenol and meta-cresylic acid. It is used as disinfectant, photographic developer, varnish remover, rubber reclaimer or in the formulation of fumigating compositions, nitrocresol explosives, intermediates, ink, paint or in the production of synthetic resins. Its molecular and structural formula are as follows: Molecular Formula StructuralHFormula CH,C,H,OH 0 I I \ / C"3 mCRESOL In preparation IS0 of this standard, considerable assistance has been derived from the following: cresylic acid and xylenols for industrial use 1897 : 1977 Phenol, o-cresol, m-cresol, p-cresol - Methods of test Determination Determination of water-Dean IS0 1897!2 : 1977 IS0 189713 : 1977 IS0 1897110 : 1982 and stark method basis on a water bath (excluding cresylic of neutral oils and pyridine Determination of dry residue after evaporation acid and xylenols) Determination of crystallizing point (excluding IS0 1897/11 : 1983 ASTM D 53 10 : 1994 crcsylic acid and xylenols) by capillary gas chromatography Standard test method for tar acid composition For the purpose of deciding whether observed or calculated, expressing IS 2 : 1960 `Rules for rounding off the rounded off value should be the a particular requirement of this standard is complied with, the final value, the result of a test or analysis, shall be rounded off in accordance with numerical values (revised)`. The number of significant places retained in same as that of the specified value in this standard. IS 14710 : 1999 Indian Standard kZlU'2-CRESOL 1 SCOPE This standard prescribes the requirements and the methods of sampling and test for meta-cresol. 2 NORMATIVE REFERENCES SPECIFICATION Table 1 Requirements for m-Cresol (Clause 3.2) Sl No. Characteristic Requirement Mehod of Test, Ref to Annex (4) B C D E F The following standards contain provisions which through, reference in this text constitute provision of this standard. At the time of publication, the editions indicated were valid. All standards are subject to revision and parties to agreements based on this standard are encouraged to investigate the possibility of applying indicated the most recent editions of the standards below: (2) (1) 0 Specific gravity at 15.6/15.6T ii) iii) Water content, percent by mass, Max Residue on evaporation, percent by mass, Max (3) I .034 0.3 0.05 0.1 12 98 iv) Neutral oil, percent by mass, Max v) Crystallization Mitt vi) point, "C, IS No. 1070 : 1992 2480 (Part 1) : 1983 Title Reagent grade water (third revision) General purpose glass thermometers: Part 1 Solid stem thermometers (second revision) Steel drums (galvanized and 2552 : 1989 ungalvanized) (third revision) Density hydrometer: 3104 (Part 1) : 1982 Requirements (first revision) (Part 2) : 1982 Methods of test and use Cfirst revision) Liquid-in-glass solid stem reference 4825 : 1982 thermometers (first revision) Methods for random sampling 4905 : 1968 3 REQUIREMENTS 3.1 Description The material shall be in the form of solid or clear liquid free of turbidity or any suspended particles when examined visually. The colour of the material shall be one of the following shades, as agreed to between the supplier and the purchaser when tested in accordance with the method prescribed in Annex A: a) b) c) d) Colourless, Very pale, Pale, and Medium dark. Assay (as cresols), percent by mass, Min G 4 PRECAUTIONS IN HANDLING The material is rapidly absorbed through skin and causes severe bums. In view of its irritating properties, precautions shall be taken while handling the material. The material shall not come in contact with the skin. Exposure to its vapour fumes and dust shall be minimum and safety goggles shall be worn to protect eyes. 5 PACKING 5.1 Packing The material shall be packed in mild steel drums (see IS 2552) or in any other suitable containers as agreed to between the purchaser and the supplier. 5.2 Marking Each container shall be securely and marked with the following: a) b) c) d) e) Name of the material, Indication of the source of manufacture, in the container, and Net mass of the material Lot or Batch number, Date of manufacture. Marking closed after filling AND MARKING 5.2.1 BIS Certification The containers Mark. may also be marked with the Standard 3.2 The material shall also comply with the requirements given in Table 1 when tested according to the test methods prescribed in Annexes B to G. 5.2.1.1 The use of Standard Mark is governed by the provisions of the Bureau oflndian Standards Act, 1986 and the Rules and Regulations made thereunder. IS 14710 : 1999 Details of conditions under which a licence for the use of the Standard Mark may be granted to manufacturers or producers, may be obtained from the Bureau of Indian Standards. 6 QUALITY Unless OF REAGENTS specified, pure chemicals and distilled water (see IS 1070) shall be employed in tests. NOTE`Pure chemicals' shall mean chemicals that do not contain impurities which affect the results of analysis. 7 SAMPLING Representative samples of the material shall be drawn as prescribed in Annex H. otherwise ANNEX A (Clause 3.1) DETERMINATION OF DEPTH OF COLOUR A-l OUTLINE OF THE METHOD Colour of Solution Solute The colour of the sample is compared against standard solutions by viewing equal depths in the Nessler cylinders. A-2 APPA-RATUS A-2.1 Nessler about 25 graduated from the by more Cylinders Quantity of Solute, g Pale Red shade Cobalt sulphate Potassium dichromate Yellow shade Cobalt sulphate Potassium dichromate Copper sulphate Medium Dark Red shade Cobalt sulphate Potassium dichromate Potassium ferricyanide 70.0 0.5 320.0 22.5 0.06 10.0 0.18 2.5 Two flat-bottomed cylinders of thin colourless glass mm in diameter and about 150 mm in length at 50 ml, The depth measured internally graduation mark to the bottom shall not vary than 2 mm in the cylinders used for the test. COLOUR SOLUTION A-3 STANDARD A-3.1 The standard colour solutions shall contain per litre the following quantities of solutes of analytical reagent quality, dissolved in distilled water. Colour of Solution Solute Quantity of Solute, g 0.90 0.015 Yellow shade White Cobalt sulphate Potassium dichromate A-3.1.1 The standard solutions except that containing potassium ferricyanide, keep well but may be used over a period not exceeding one month from preparation. The potassium ferricyanide solution shall be prepared on the day of the test. A-4 PROCEDURE Compare the sample with the standard solutions by viewing equal depths in the Nessler cylinder and report the colour and shade of the sample as not darker than that of the appropriate so~lution as typified by the description of the depth and shade of colour. Very Pale Fred shade Cobalt sulphate Potassium dichromate Cobalt sulphate Yellow shade Potassium dichromate Copper sulphate 6.0 0.015 4.0 0.075 1.0 2 IS44710:1999 ANNEX 3 [Clause 3.2 and Table 1,SI No. (i)] DETERMINATION B-l APPARATUS B-l.1 Hydrometer Conforming to the requirement Table 1 in IS 3104 (Part 1). B-l.2 Thermometer of L.50 series of OF SPECIFIC GRAVITY to 100°C and marked with figures at every IO degrees. B-l.3 Thermostat B-2 PROCEDURE Take the sample in a clean dried glass cylinder and place it in a thermostat maintained at 15°C. Determine specific gravity of the material by the method as prescribed in 2 of IS 3 104 (Part 2). Mercury in glass, type, graduated in one degree from 0 ANNEX C [Clause 3.2 and Table 1, Sl No. (ii)] DETERMINATION OF WATER CONTENT C-l OUTLINE OF THE METHOD The material is distilled in the presence of an appropriate solvent, in a Dean and Stark apparatus. The condensable, assumed to be water, is collected in the receiver and the volume is determined at ambient temperature. C-2 REAGENTS Any of the following water, may be used. C-2.1 Toluene C-2.2 Solvent Naphtha reagents, which is free from 96 percent shall distill below 160%. C-2.3 Xylene The difference, between distillation temperature at which 5 percent and 95 percent of the volume taken have been collected shall not exceed 5°C and this range shall include 137.0°C and 145.5"C. C-3 APPARATUS C-3.1 Dean and Stark Apparatus DISTILLATION Comprising 500 ml glass distillation flask fitted to a condenser with a 2 ml receiver having a maximum error of ltO.02 ml. A typical assembly of the Dean and Stark apparatus with a suitable form of condenser is shown in Fig. 1. FIG. 1 TYPICAL ASSEMBLY OF DEAN STARK APPARATUS AND 3 IS 14710 : 1999 C-4 PROCEDURE Weigh accurately about 200 g of the sample and transfer to the flask of the Dean and Stark apparatus. Add 100 ml of the solvent. Attach the flask to the apparatus so t!rat condensate fails from the end of the condenser at the rate of 2 to 5 drops per second. Continue the distillation until condensed water is no longer visible in any part of the apparatus except the bottom of the graduated tube and until the volume of water collected remains constant. Remove any persistent ring of condensed water formed in the condenser tube by increasing the rate of distillation by a few drops per second. Bring the temperature of the water volume. collected to ambient level and note its C-5 CALCULATION Water content, percent by mass where V M = volume of water temperature, ml collected at ambient = V x 100 A4 = mass of sample taken for test, g It is assumed that density of water collected tube, at ambient temperature, is 1.OOg/ml. in the NOTE graduated ANNEX D [Clause 3.2 and l'able 1, Sl No. (iii)] DETERMINATION D-l OUTLINE OF THE METHOD OF RESIDUE ON EVAPORATION mixed before the sample is taken. Precaution shall be taken to avoid overheating or contamination by moisture. The material is evaporated on a boiling water bath and the residue is dried in an oven at 105 f 2% for 1 h. D-2 APPARATUS D-2.1 Platinum 150 ml. D-2.2 Water Containing Bath boiling water. Dish Place the dish and its contents on the boiling water bath in a well-ventilated fume cupboard (see Note) and evaporate the material to dryness. Remove the dish from the water-bath, wipe the outside with a tissue and continue heating in the oven, maintained at 105 f 2°C for 1 h. Remove the dish from the oven, allow it to cool to ambient temperature in a desiccator and weigh rapidly to the nearest 0.000 1 g. NOTE - m-cresol and its vapours are toxic and corrosive. It is essential that evaporation is carried out in a well-ventilated fume cupboard. D-2.3 Electric Oven at 105 f 2°C. Capable of being maintained D-3 PROCEDURE D-4 CALCULATION Dry residue on evaporation, percent by mass where M = mass of sample taken for test, g; M, = mass of dish with the residue, g; and M2 = mass of empty dish, g. = Ml -M2 Dry the platinum dish for 1 h in the oven, maintained at 105 f 2°C allow to cool in a desiccator and weigh it to the nearest 0.000 1 g. Weigh rapidly and directly in the weighing dish, about 20 g of the material nearest to 0.000 1 g. NOTE - If the sample is in the form ofa solid crystalline mass or contains crystals, it shall be completely melted and thoroughly M x 100 4 IS 14710: 1999 ANNEX E [Clause 3.2 and Table 1, SZNo.(iv)] DETERMINATION E-l OUTLINE OF THE METHOD OF NEUTRAL OIL Neutral oils and pyridine bases are distilled out of the alkaline solution of the material. The volume~of neutral oils thus collected is measured. E-2 REAGENTS E-2.1 Sodium Chloride 2 percent by mass. E-2.2 Sodium Hydroxide Solution Solution - 28 ID 27 percent by mass. E-2.3 Dilute Hydrochloric 0.1 N. E-3 APPARATUS E-3.1 Distillation Assembly Acid With 1 000 ml capacity and of round bottom flask (see Fig. 2). All dimensions in millimetres. FIG. 3 DETAILSOF SPLASHHEAD AND BUBBLER TUBE FIG. 2 APPARATUS FORDETERMINATION OFNEUTRAL OILS AND PYRIDINE BASES E-3.2 Splash Head and Bubbler Tube see Fig.3. E-3.3 Graduated Separating Funnel Receivers see Fig.4. E-3.4 Liebig Condenser All dimensions in millimetres. FIG. 4 SEPARATING FUNNEL RECEIVER 5 see Fig.5. E-4 PROCEDURE E-4.1 Before commencing the test it is essential to ensure that the receiver and ~conical flask are scrupulously clean. Washing with detergent, followed by thorough rinsing in tap water and distilled water, is usually adequate. E-4.2 Measure 100 ml of the sample at laboratory temperature into the round bottom flask. Add 170 ml of the sodium hydroxide solution, followed by 100 ml of water using the same measuring cylinder, without intermediate cleaning or rinsing, for all three operations. Mix thoroughly. To prevent bumping add a small fragment of porous pot. Measure 25 ml of the sodium hydroxide solution into the inner bubbler tube. Fill the graduated portion of the receiver with the sodium chloride solution to prevent lodgment of the neutral oil, and assemble the apparatus as shown in Fig. 2. E-4.3 Distil the material at such a rate that 100 ml of condensate is collected within lo-15 min. Ensure that the condensate runs down the inside surface of the receiver and not directly on to the liquid surface. Towards the end of the distillation turn of the water and drain approximately two-thirds of the condenser to melt any condensed solids. Do not allow steam to issue from the end of the condenser at any time during the distillation. E-4.4 Report All dimensions in millimetres. FIG. 5 LIEBIG CONDENSER The volume, in millilitres, of neutral oils obtained (E-4.3) from 100 g of sample taken for the test, as mass percent of neutral oil. 12 TO 13 OD ANNEX F [Clause 3.2 and Table 1, SZNo. (v)] DETERMINATION OF CRYSTALLIZING POINT F-l OUTLINE OF THE METHOD The material in liquid form is cooled and the crystallizing point is determined by observation of the temperature during crystallization under defined conditions. F-2 APPARATUS A suitable crystallizing the following. F-2.1 Crystallizing point apparatus consisting of bottom of the bulb is about 15 mm from the bottom of the crystallizing tube (see Fig. 6) F-2.2 Outer Protection Tube Nominal dimensions of 160 mm x 38 mm, weighed with lead shots or similar material. This tube is flanged so that it may be supported centrally in the metal plate covering the water bath F-2.3 Stirrer Made of glass, with a loop of outside diameter 18 mm, to surround the thermometer. F-2.4 Water Bath Consisting 6 of a 1 000 ml tall form beaker containing Tube Nominal dimensions 150 mm x 25 mm, sealed with a stopper, which carries the stirrer and the thermometer. The thermometer is so fixed in the stopper that the IS 14710 : 1999 F-3 PROCEDURE Transfer 20 ml of the material directly into the crystallizing tube and insert the stopper carrying the appropriate thermometer and the stirrer. If-the material has started to crystallize, heat gently until it melts completely again and then cool rapidly to determine the approximate crystallizing point. Warm the tube in the water bath at a temperature about 5°C above this point, so that the crystals melts, except for a trace necessary for seeding. Replace the crystallizing tube in its jacket with the water in the apparatus maintained at a temperature between 6°C and 8'C below the expected crystallizing point. Stir the material gently and continuously and record the thermometer reading at 30 s intervals. The crystallizing point corresponds to the highest of the first five consecutive readings during which the temperature remains constant with 0.05"C. If supercooling occurs, as shown by a rise in temperature, observe the constant temperature after the rise. A temperature rise of 1°C is the maximum allowable. If a constant temperature is not retained over the first five readings after the rise in temperature, record six readings commencing with the point at which the maximum temperature is first attained. All dimensions in millimetres. FIG. 6 APPARATUSFORDETERMINATION OF CRYSTALLIZING POINT water to within 20 mm of the top and covered with a metal plate. This plate shall have two holes, one in the centre which carries the outer protection tube and the other, to one side, through which the thermometer passes and is held by a rubber ring. F-2.5 Thermometer see IS 4825. F-2.6 Thermometer see IS 2480 (Part 1). for General Purpose for Precision Use Plot the complete cooling curve of temperature against time and draw a straight line to lie evenly between the first and second and between the fifth and sixth points mentioned above. Extend this line to meet the section of the cooling curve before the temperature rise. Record the temperature corresponding to the point of intersection, as the crystallizing point. Correct the temperature by applying the correction for thermometer error. F-3.1 Report Report the crystallizing point determined in F-3 rounded to the nearest O.l"C with a mention whether the sample was tested in the dried or undried condition. 7 IS 14710 : 1999 ANNEX G [Clause 3.2 and Table 1, SZ No. I] ANALYSIS G-l OUTLINE OF IMET'-CRESOL BY GAS CHROMATOGRAPHY G-3.2 m-cresol G-3.3 o-cresol G-3.4 p-cresol G-3.5 Phenol G-3.6 Toluene G-3.7 Other expected G-4 PREPARATION impurities OF COLUMN Purity 99.5 percent, Min OF THE METHOD A known amount of internal standard is added to the sample. A portion of the sample is chromatographed and the amounts of impurities are calculated relative to the amount of internal standard added. The sum of all impurities when subtracted from 100.00, it gives the purity of m-cresol. Results are reported in mass percent. G-Z APPARATUS G-2.1 Chromatograph Any gas chromatograph equipped with either a thermal conductivity or hydrogen flame ionization detector consistent with the type of column used. The detection system shall be sufficiently sensitive to produce a minimum response equivalent to 0.01 percent of components of interest on a recorder or electronic integrator. G-2.2 Chromatograph Column G-4.1 The method used to prepare columns is not critical provided that the prepared column produces the desired separation. A typical combination of conditions is given below: Tubing a) b) Length Inside diameter Stainless Steel 3 000 mm 3 mm FAP-SON WAW 60180 gas, flow rate nitrogen, 210°C 150°C 0.04 2.5 mm/min 0.3 pl (5 percent solution in benzene) 40 ml/min Chromosorb Solid support Mesh Carrier Injection detector temperature Column temperature Recorder a) b) Range Speed Any column may be used which is capable of resolving all significant impurity components from m-cresol and the added internal standard. Column may be either packed or capillary type. G-2.3 Recorder Any recorder with 2 mVorless full-scale response of one second and a chart speed of 75 to 150 cm/h is satisfactory, provided that the recorder-detector system shall repeat to 0.01 mass percent. ~G-2.4 Integrator An integrator when used in conjunction with the detector, it shall provide repeatable response to 0.01 mass percent. G-2.5 Microsyringe G-2.6 Volumetric G-2.7 Volumetric G-3 REAGENTS G-3.1 Carrier Gas Chromatographic grade helium or hydrogen for use on thermal conductivity detector units or nitrogen, helium or argon for use on flame ionization detector units. 10 pl. 100 ml capacity. 1 ml. Sample size NOTE-The above gas chromatographic conditions are suggestive.However, other GC with different columns may be used provided standardization/calibrations are done after setting the chromatographic conditions for the required resolutions. G-5 PROCEDURE G-5.1 Calibration Prepare a synthetic given below: mixture from pure compounds as Flask Pipette - Weight m-cresoi o-cresol percent 94 2 2 1 1 p-cresol phenol toluene Pipette using a pipette bulb 1.O ml of internal standard into a 100 ml volumetric flask and dilute to mark with 8 IS 14710 : 1999 above synthetic mixture and mix well. From this pipette out 5 ml in another 100 ml volumetric flask and dilute to volume with benzene and mix well. Inject 0.3 yl of the benzene solution. Determine the response of each component except that of m-cresol relative to the internal standard (&o-octane or n-octane or nundecane) and determine the response factor of each compound relative to the internal standard. Measure the area of each peak except m-cresol. a : RF,L?L_ A4 A, where RF, = response Ai As = peak blend; = peak area of internal tion blend; AB, = peak area of impurity stock; ABs = peak area of internal base stock; c, ci Calculate = concentration percent; and = concentration blend, mass. response AB, C, Ci factor for component i; area of impurity i in calibration in calibrabase standard in m-cresol standard in m-cresol standard, mass of internal ~of impurity in calibration factors to nearest 0.001. i PIG. 7 TYPICAL CHAROMATOGRAM FOR ESTIMATION OF M-CRESOL c. I G-5.2 Pipette 1.O ml of internal standard into a 100 ml volumetric flask and dilute to the mark with the sample and mix well. Charge an appropriate amount to the chromatograph. Measure the area of all peaks except the m-cresol peak (A typical chromatogram is shown in Fig. 7.). G-6 CALCULATION Calculate the amounts of individual impurities and the total concentration of all impurities, sum up area of all impurities peaks and calculate m-cresol content as follows: m-cresol = 100 - C, where C, = total concentration mass percent. of all impurities in = Ai ' cs A,xRF, C, = Ci IS 14710 : 1999 ANNEX H (Clause 7) SAMPLING H-l GENERAL SAMPLING REQUIREMENTS OF OF m-CRESOL removable stopper or top, to which is attached a light chain (see Fig. 8). The bottle or can is fastened to a suitable pole. For taking a sample, it~is lowered in the tank to the required depth, and the stopper or top is removed by means of the chain for filling the container. H-l.1 In drawing, preparing, storing and handling test samples, the-following precautions and directions shall be observed H-l.2 Samples shall not be taken in an exposed place. H-l.3 The samples, the material being sampled, the sampling instrument and the containers for samples shall be protected from adventitious contamination. H-l.4 To draw a representative sample, the contents of each container selected for sampling shall be mixed as thoroughly as possible by shaking or stirring or both, or by rolling, so as to bring all portions into uniform distribution. H-1.5 The samples shall be placed in suitable, clean, dry and air-tight glass containers, preferably of amber or blue colour. H-l.6 The sample containers shall be of such a size that they are almost, but not completely, filled by the sample. H-l.7 Each sample container with a suitable stopper after full details of sampling, such the year of manufacture of number and the name of the shall be taken to ensure that contaminate the sample. shall be sealed air-tight tilling and marked with as the date of sampling, the material, the batch sampler. Particular care sealing methods do not FIG. 8 SAMPLINGBOTTLEOR CAN H-2.2 Sampling Tube H-l.8 Samples shall be stored in such a manner that the temperature of the material does not vary unduly from the normal temperature. H-l.9 m-cresol may burn the skin and may be absorbed into the system through the skin. It is essential for the sampler to wear gloves, preferably of polyvinyl chloride, and also a face shield. Inhalation of the vapours from hot material is to be avoided. H-2 SAMPLING INSTRUMENT instruments may be It is made of metal or thick glass and is about 20 to 40 mm in diameter and 400 to 800 mm in length (see Fig. 9). The upper and lower ends are conical and reach 5 to 10 mm in diameter at the narrow ends. Handling is facilitated by two rings at the upper end. For taking a sample, the apparatus is first closed at the top with the thumb or a stopper and lowered until the desired depth is reached. It is then opened for a short time to admit the material and finally closed and withdrawn. For small containers, the size of the sampling may be altered suitably. H-3 SCALE H-3.1 Lot In a single consignment, all the containers of the same size and drawn from the same batch of manufacture shall constitute a lot. If a consignment is known to consist of containers of different sizes or of different batches of manufacture,mthen the containers belonging to the same size shall constitute a separate lot. In case 10 tube The following used: a) b) forms of sampling OF SAMPLING Sampling bottle or can for taking samples from various depths in large tanks, and Sampling tube. Bottle or Can with H-2.1 Sampling It consists of a weighed bottle or metal container IS 14710 : 1999 H-3.3 Sampling k-5 TOlOmm $ from Tanks or Vessels Each of the tanks or vessels in the lot shall be sampled separately for determining the conformity of the lot of the requirements of the specification. H-4 PREPARATION H-4.1 Test Samples OF TEST SAMPLES from Containers To ensure that the-sample taken from each container is fairly representative, the contents shall be mixed thoroughly, when possible by shaking or stirring or rolling. Draw small samples of the material from various depths with the help of the sampling tube. The approximate quantity of the materials to be drawn from a container shall be a little more than thrice the quantity required for testing purposes as indicated in H-5.1 and H-5.2. H-4.1.1 Out of the material drawn from each individual container, a small but equal quantity of material shall be taken and thoroughly mixed to form a composite sample, sufficient for carrying out triplicate determination for all the characteristics specified under H-5.2. The composite sample shall be divided into three equal parts, one for the purchaser, another for the supplier and the third for the referee. H-4.1.2 The remaining portion of the material from each container shall be divided into three equal parts, each forming an individual sample.One set of individual samples representing the containers selected shall be for the purchaser, another for the supplier, and third for the referee. H-4.1.3 All the individual and composite samples shall be transferred to separate sample containers. These containers shall then be sealed air-tight with stoppers and labelled with full identification particulars given in H-1.7. H-4.1.4 The referee test samples, consisting of a composite sample and a set of individual samples, shall bear the seals of both the purchaser and the supplier. They-shall be kept at a place agreed to between the two, to be used in case of any dispute. H-4.2 Test Samples from Tanks or Vessels -5TOlOmm# FIG. 9 SAMPLING PLAIN TUBE the consignment is in large tanks or vessels, then the tanks or vessels belonging to the same batch of manufacture shall constitute a lot. H-3.1.1 For ascertaining the conformity of the lot to the requirement of the specification, tests shall be carried out for each lot separately. H-3.2 Sampling from Containers The number of containers to be selected for sampling shall ~depend on the size of the lot and shall be in accordance with Table 2. Table 2 Scale of Sampling Lot Size No. of Containers to be Selected (2) 5 6 I 8 9 10 (1) up to 100 101 " 200 201 w300 301 " 400 401 11 500 Above 501 H-3.2.1 The containers shall be selected at random in order to ensure the randomness or selection procedure given in IS 4905 may be followed. 11 H-4.2.1 For drawing a sample from a tank or vessel, lower the closed sampling bottle or can (H-2.1) slowly to the required depth, open and fill it at that depth. Three samples shall be obtained at levels of one-tenth of the depth of the liquid from the top surface (top sample), one half of the depth (middle sample) and nine-tenths of the depth of the liquid the top surface (lower sample). All the three samples thus obtained from a tank or vessel shall be mixed together in a IS 14710: 1999 clean dry container and shall be divided into three parts, one for the purchaser, another for the supplier and the third for the referee. Each of the tanks or vessels in the lot shall be sampled in the above manner and separate samples obtained for each of the tanks or vessels. The approximate quantity of the material to be drawn from~a tank or vessel shall be a little more than thrice the quantity required for carrying out tests for ~a11the requirements prescribed in H-5.1 and H-5.2. H-4.2.2 All the samples thus obtained from tanks or vessels in the lot shall be transferred to separate sample containers. These containers shall then be sealed airtight with stoppers and labelled with full identification particulars given in H-1.6. H-4.2.3 The referee test samples, consisting ofthe samples from the tanks-or vessels in the lot, shall bear the seals of both the purchaser and the supplier. They shall be kept at a place agreed to between the two, to be used in case of any dispute. H-5 NUMBER OF TESTS H-5.1 Tests for the determination of crystallization point and residue on evaporation shall be conducted on each of the individual samples (see H-4.1.2). H-5.2 Tests for the determination of the remaining characteristics namely, colours, specific gravity, water content, neutral oil and assay shall be conducted on the composite sample (see H-4.1.1). H-6 CRITERIA FOR CONFORMITY H-6.1 The lot shall be declared as conforming to the requirements for crystallization point and residue on evaporation if test results for each of the individual samples tested in respect of these characteristics satisfy the requirement as given in Table I. H-6.2 For declaring the conformity of the lot to the requirements of all other characteristics tested on the composite sample (see H-5.2) results for each of the characteristics shall satisfy the relevant requirements given in the specification. 12